Furnace body supporting structure for blast furnaces

ABSTRACT

A furnace body supporting structure for blast furnaces comprising a plurality of supporting columns arranged along the outer periphery of the furnace body and resilient bodies on the supporting columns or on beams fixed to the supporting columns and interposed between the supporting columns and a ring plate installed on the bottom of a furnace shaft or between beams and brackets installed on the furnace shaft to absorb the weight of the furnace body, and thrust blocks fixed between the ring plate and supporting columns or between the brackets and beams respectively to prevent the horizontal movement of the furnace body.

United States Patent [191 Miyajima et al.

[ May 28, 1974 FURNACE BODY SUPPORTING STRUCTURE FOR BLAST FURNACES [76] Inventors: Nobuo Miyajima, 107,

Sakurahonmachi, Minama-ku, Nagoya; K010 Kaneko, 7-1-406, Higashiyamada, Hukishima-cho, Tokai; Iwao Ohnuki, 5-12-102, Miyazu-Shinkaizan, Agui-cho, Chita-gun, Aichiken; Noboru Okubo, -1 19-44, Aza-Kamiwashibetsu, Noboribetsu-cho, Horobetsugun, Hokkaido, all of Japan [22] Filed: Dec. 27, 1971 [21] Appl. N0.: 211,923

[52] US. Cl. 266/25 [51] Int. Cl C2lb 7/00 [58] Field of Search 266/25, 24; 52/573 [56] References Cited UNITED STATES PATENTS 2,052,928 9/1936 Harris 266/25 X 3,400,922 9/1968 Langlitz 266/36 3,548,678 12/1970 Phillips 3,630,507 12/1971 Grea'ves 266/25 [57] ABSTRACT A furnace body supporting structure for blast furnaces comprising a plurality of supporting columns arranged along the outer periphery of the furnace body and resilient bodies on the supporting columns or on beams fixed to the supporting columns and interposed between the supporting columns and a ring plate installed on the bottom of a furnace shaft or between beams and brackets installed on the furnace shaft to absorb the weight of the furnace body, and thrust blocks fixed between the ring plate and supporting columns or between the brackets and beams respectively toprevent the horizontal movement of the furnace body.

12 Claims, 10 Drawing Figures PATENTEDNAY 28 1914 saw 1 or s FIG. 1'

Nobuo K526 lwao Noboru INVENTORS Mz'yajima Kaneko Ohnuki Okubo ATTORNEY;

PATENTEDMAY28|9M 3813088 SHEEI 2 N 5 G- 3 FiG.4

INVENTORS Nobuo Miyajima K626 Kaneko wao Ohnuki Noboru Okubo BYWM J? ATTORNEYS PATENTEUHAY 28 I974 SHEET 3 0f 5 FIG. 5..

FiG. 6

I NVENTORS Mi ya j i m a Kan eko Nobuo lwao Ohnuki Noboru Okubo W-.,,-, Q? 3 ATTORNEB INVENTORS Nobuo Miyajima K 626 K aneko llvwao ghnuki oboru kubo BY W m QM ATTORNEYS PATENTEDMAY28 m4 sum sofs F|G.8 A

O 111 II I FlG. 8-1

Displacement of a dish spring FIGS-2 B b o I t I I o INVENTORS Nobuo Miyajimg K 625 Kaneko /W00 hnuki Noboru Okub M @Mu ATTORNEIQ,

FURNACE BODY SUPPORTING STRUCTURE FOR BLAST FURNACES BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to a furnace body supporting structure for blast furnaces.

FIGS. 1 and 2 are diagrammatic views of a conventional furnace body supporting structure for blast furnaces.

FIG. 3 is a diagrammatic view showing an embodiment of the present invention.

FIG. 4 is a diagrammatic plan view of a supporting structure of one of four supporting columns as an example of a furnace body supporting system according to the present invention.

FIG. 5 is an enlarged sectional view taken on line AA' in FIG. 4.

FIG. 6 is an enlarged plan view of a thrust block.

FIG. 7 is an elevation view showing an embodiment of a supporting structure provided with brackets in the furnace shaft part.

FIGS. 8 to 8-2 are graphs showing an example of the characteristic of a spring according to the present invention.

DESCRIPTION OF THE PRIOR ART- Heretofore, there have been various attempts made in the design of a furnace body supporting device to absorb thermal strains generated in the initial period'(for the first one or two months) of the operation of a blast furnace. In such a conventional furnace body structure which is shown in FIG. I, wherein a ring plate 3 is provided between the upper part of the bosh l and the lower part of the furnace shaft 2 so that the weight of the furnace body can be borne by supporting columns 5 through a liner 4, the thermal expansion in the initial period of the operation of the blast furnace is absorbed by the adjustment of the liner 4. Consequently until the liner is adjusted, a load will be applied to the bosh l and the hearth part 6. Therefore, the bosh I and the hearth part 6 are required to have a strength sufficient to support the weight of the furnace body. Moreover, the adjustment of the liner is operationally not easy due to a thermal expansion of the furnace shell in the initial period of the furnace operation or due to changes in the thermal expansion caused by the furnace shell temper ature changing according to the furnace operating conditions.

In another conventional system there is a construction as is shown in FIG. 2, wherein a flexible joint a is provided to absorb the thermal strain of a furnace shell. This construction has the following defects the flexible joint 0 is likely to crack, and once it cracks, the airtightness will deteriorate and particularly in a modern blast furnace which is operated with a high pressure, troubles in the operation will be further aggravated; further, where stave cooling is adopted to cool the furnace body of the blast furnace it will be difficult to provide the furnace shell with the flexible joint a because of the cooling pipe connections around the furnace body.

SUMMARY OF THE INVENTION The present invention has advantageously solved such difficulties of the conventional furnace body structures as described above and provides a furnace body supporting structure for blast furnaces comprising a ring plate installed at the bottom of a furnace shaft for supporting the same, a plurality of supporting columns 5 arranged along the outer periphery of a furnace body respectively to support the ring plate through resilient members on the respective supporting columns and interposed between the ring plate and the supporting column respectively to absorb the weight of the the furnace body. The furnace body supporting structure of the present invention may also be composed of brackets installed on the furnace shaft, a plurality of supporting columns along the outer periphery of the furnace body respectively, beams fixed to the supporting columns respectively to support the brackets through resilient members on the beams interposed between each beam and bracket to absorb both the weight of the furnace body and horizontal forces thereon.

Further, the present invention provides a furnace body supporting structure additionally comprising vertically movable thrust blocks respectively, which are installed between the ring plate and the supporting column or between the beam and bracket, for the purpose of preventing the movement of the furnace body in the horizontal direction.

By the structures as above-described, the present invention absorbs the deformation of the furnace body due to the thermal strain or the like from the thermal expansion of an iron shell on the lower part of a blast furnace in the initial period of the operation of the blast furnace by dint of, for instance, the elongation and contraction of the resilient bodies on the furnace body supporting columns, and further in the caseof a horizontal movement of the furnace body due to an earthquake or storm the structures transmit the horizontal load to the furnace body supporting columns and prevent the movement of the furnace body in the horizontal direction by means of said thrust blocks.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The resilient body is preferably a dish spring or the like. When using a dish spring, it is mounted on the supporting column so as to be positioned between the supporting column and the ring plate by means of a fitting pin within the dish spring. The mounting of the fixing the pin on the supporting column can be by any proper method such as inserting the pin into a hole made in the supporting column or welding or bolting the pin to the supporting column.

However, as the place in which the resilient body is installed is generally enveloped in a corrosive atmosphere containing heated sulfur dioxide and much dust, it is preferable to provide a cover outside the dish spring and to pour oil or nitrogen into the interior thereof to prevent the entry of outside air.

The thrust block is constructed of an upper thrust block member and a lower thrust block member, said upper thrust block member being mounted on the ring plate or a furnace body supporting bracket, while the lower thrust block member is mounted on the furnace body supporting column or beam, and the thrust block members are freely movable in the vertical direction relative to and yet prevent the movement of the furnace body in the horizontal direction. The thrust block may be in any convenient form such as of a pair of cylinders or prisms.

In the initial period of the operation of a blast furnace the difference in the thermal expansion, that is, the difference in dimensions, produced by the temperature difference between the outside wall of the furnace shell and the supporting column is large but, when the temperature of the outside wall of the furnace shell then reaches a steady state, the temperature difference between the shell and the supporting column becomes substantially constant.

Taking account of this fact, the present invention is to support the weight of the furnace body on the supporting columns through a resilient body. As for the resilient body, one which has a strength sufficient for this purpose must be selected.

The manner of using such resilient body is as follows: The body is initially forcibly compressed prior to the operation of the blast furnace and is relieved from the restraint of the clamp screws before heat is applied to the furnace body. In such a condition the resilient body is fully compressed. Then, with the start of the operation of the blast furnace, it extends following the thermal expansion of the furnace body, and in normal operation it supports the furnace body with a proper expansion. For this purpose the fitting pin is preferably threaded at the tip thereof is released before the operation of the blast furnace begins. At the same time the thrust block is mounted so as to be freely movable in the same direction as the resilient body. Consequently, it serves effectively to prevent the sideways sway of the furnace body irrespective immediately of the extension and contraction of the furnace body caused by the operation of the blast furnace and to transmit to the supporting columns a horizontal load when such a load is generated.

An embodiment of the present invention will now be explained in detail in the following with reference to the above described drawings.

In FIG. 3, a ring plate 3 is mounted at the lower end of a furnace shaft 2 and supporting columns (four at regular intervals on the periphery) are installed under outwardly extending projections on said ring plate 3 with respective spring members 7 and 7' between the ring plate 3 and the columns 5.

In conventional constructions the shaft weight has been supported by a bosh l and hearth part 6, but according to the present invention the weight is absorbed by the supporting columns 5 and the spring members 7 and 7' so that the load on the bosh l and the hearth part 6 will be greatly reduced.

In FIG. 4 which is a plan view of a projection on the ring plate over a supporting structure of one of supporting columns there are provided thrust blocks 8 to transmit a horizontal load when generated and one is concave and is directed to the center of a circle corresponding to the cross section of the furnace. Resilient members 9 each comprise a proper dish spring or the like selected according to the load imposed thereon by the weight of the blast furnace.

In FIG. 5 the resilient means is shown as a dish spring 10 arranged around a pin 11 between dish spring receiving plates 12 and 12 and further covered with cover plates 14 and 14 and generally cylindrical covers 15 and 15' extending toward each other from the cover plates and one telescoping into the other. A seal packing 13 is provided between the lower cover plate and the top of the supporting column and between the lower spring receiving plate and the lower cover plate.

In order to tightly fasten the dish spring a nut 16 is threaded onto the threaded upper end of the pin 11.

Thereby, a spring assembly is provided between the supporting column 5 and the ring plate 3.

With the expansion and contraction of the furnace shell the dish spring 10 will expand and contract through the ring plate 3 and with the expansion and contraction of the dish spring 10 the covers 15 and 15 will slide telescopically to sufficiently absorb the expansion and contraction of the furnace shell, whereby the deformation thereof may be prevented. On the inside surface of the cover 15' there is provided a sealing ring 17 which seals against the outside of cover 15, as illustrated, which serves to prevent the entry of sulfur dioxide and dust or the like into the dish spring 10 in order to protect the dish spring from being adversely affected on account of corrosion or the like caused by the entry of sulfur dioxide and dustas a result of the sliding of covers 15 and 15.

Further, for the purpose of positively protecting the dish spring against corrosion or the like oil or grease is fed into the space around the dish spring 10 through an oil feeding port 18 in the upper part of the pin 11.

In FIG. 6, 19 is a rectangular upper thrust block and 20 is a lower U-shaped thrust block, with the upper block being fixed to the ring plate 3 and the lower block being fixed to the top of the supporting column, with the block being freely movable vertically relative to each other, but engaging each other to transmit horizontal loads. They transmit a horizontal load to the sup porting columns and prevent the furnace body from moving in the horizontal direction when a horizontal load is generated.

FIG. 7 shows an example of a supporting structure, in which brackets 21 are provided on the furnace shaft 2, and wherein the weight of the furnace body is supported by supporting columns 5 through resilient bodies 7 mounted between a beam 22 on each supporting column and a bracket 21. This structure has the advantage that the working place can be made wide so that during operating of the furnace the access to the furnace can be improved.

The change in the reaction force of the supporting column 5 fitted with such a spring mechanism as abovedescribed will be explained.

FIGS. 8 to 8-2 show the characteristics-of a dish spring, wherein the abscissa represents the displacement of the spring and the ordinate the vertical load. The zone A represents the load applied to the boshhearth shell portion of the furnace, while the zone B represents reaction force of the dish spring, that is, the load applied to the supporting column.

FIG. 8-1 shows how to use this dish spring. Initially the dish spring is set in a completely compressed state. In this state the load [2 (reaction force of the dish spring) is applied to the supporting column. a is the total loads of the furnace shaft. 0 is a load applied to the bosh-hearth shell at the time the displacement of the dish spring is 0. The dish spring is used in such a way as is gradually relaxed from the completely compressed state. The point 1 in the figure is to be read as a displacement 0 (designating the completely compressed state). Therefore, the displacement is to be considered as increasing from the point 0 in the left direction.

FIG. 8-2 shows a load-spring displacement diagram at the time, when the furnace body has reached a temperature of a normal state. That is, when the displacement of the spring reaches d (an elongation of the boshhearth shell due to the thermal expansion), the load ap plied to the bosh-hearth shell becomes 0' and the reaction force of the dish spring, that is, the load applied to the supporting column is indicated by 1), showing that the reaction force of the spring does not decrease proportionately with the displacement of the spring, whereby a large reaction force may be obtained, which is one of important advantages of the present invention.

In these FIGS. l represents the state of the spring at the time of initially mounting the spring between the blast furnace and the supporting column respectively, that is, at the time of starting the operation of the blast furnace, l- I] in FIG. 8 represents the displacements of the spring after the operation of the blast furnace has started, but before reaching the normal operating state and II III in FIG. 8 represents the displacements of the spring in the normal operating state.

By carry out the present invention, the following advantages can be obtained.

Where a ring plate, which transmits the load of a furnace body, is supported by supporting columns through spring devices interposed between the ring plate and the supporting columns, the weight of the furnace body is kept stable during the time from the beginning of the operation of a blast furnace to the normal state of operation thereof, and further the horizontal load or the like is borne by thrust blocks so that the furnace body may be supported by supporting columns without being overburdened therewith. Further, once a blast furnace is fitted with the device of the present invention, the expansion and the contraction of the steel shell of the blast furnace will be limited within a substantially limited range by means of the spring device even with the variation of the temperature of the furnace shell due to banking and the like. Consequently, the reliability of the furnace body will be increased and safety will be guaranteed for the operation of the blast furnace over a long period. Moreover, such an operation as a wedgein operation for the adjustment of a liner, as was carried out in a conventional furnace, becomes unnecessary with the present invention. The present invention can also be applied to a supporting structure consisting of large-sized beams and brackets for transmitting a load larger than that of the furnace shaft.

While the present specification describes a supporting structure for blast furnaces the present invention can also be applied to supporting structures of any other equipment of the same type.

What is claimed is:

l. A furnace body supporting structure for blast furnace having a furnace shaft, comprising a ring plate on the bottom of the furnace shaft, a plurality of supporting columns arranged along the outer periphery of the furnace body, and spring means for absorbing the expansion and contraction of the furnace due to heating during operation and mounted between the respective supporting columns and the ring plate so as to be expandable and contractable in the vertical direction.

2. A furnace body supporting structure as claimed in claim 1 in which said spring means comprises preloading means for loading said springs prior to the mounting of said ring plate on the spring means.

3. A furnace body supporting structure as claimed in claim 1 in which said spring means comprises a dish spring.

4. A furnace body supporting structure for blast furnaces having a furnace shaft, comprising brackets on the furnace shaft, a plurality of supporting columns arranged along the outer periphery of the furnace body, a beam mounted on each of the supporting columns and extending toward the furnace body, and spring means for absorbing the expansion and contraction of the furnace due to heating during operation and mounted between the respective beams and brackets so as to be expandable and contractable in the vertical direction. I

5. A furnace body supporting structure as claimed in claim 4 in which said spring means comprises preloading means for loading said springs prior to the mounting of said brackets on said beams.

6. A furnace body supporting structure as claimed in claim 4 in which said spring means comprises a dish spring.

7. A furnace body supporting structure for blast furnaces having a furnace shaft, comprising a ring plate on the bottom of the furnace shaft, a plurality of supporting columns arranged along the outer periphery of the furnace body, spring means for absorbing the expansion and contraction of the furnace due to heating during operation andmounted between the respective supporting columns and the ring plate so as to be expandable and contractable in the vertical direction, and a thrust block mounted between said ring plate and the corresponding supporting column and composed of an upperthrust block member and a lower thrust block member movable vertically relative to each other, the upper thrust block member being fixed to the ring plate and the lower thrust block member being fixed to the supporting column and the block members abutting each other to transmit to the supporting columns hori- .zontal loads due to movement of the furnace body in the horizontal direction.

8. A furnace body supporting structure as claimed in claim 7 in which said spring means comprises preloading means for loading said springs priorto the mounting of said ring plate on the spring means.

9. A furnace body supporting structure as claimed in claim 7 in which said spring means comprises a dish spring.

10. A furnace body supporting structure for blast furnaces having a furnace shaft, comprising brackets on the furnace shaft, a plurality of supporting columns arranged along the outer periphery of the furnace body, a beam mounted on each of the supporting columns and extending toward the furnace body, spring means for absorbing the expansion and contraction of the fur- I nace due to heating during operation and mounted between the respective beams and brackets so as to be expandable and contractable in the vertical direction and a thrust block mounted between each beam and the corresponding bracket and composed of an upper thrust block member and a lower thrust block member movable vertically relative to each other, the upper thrust block member being fixed to the bracket and the lower thrust block member being fixed to the beam and the block members abutting each other to transmit to the supporting columns horizontal loads due to movement of the furnace body in the horizontal direction.

11. A furnace body supporting structure as claimed in claim 10 in which said spring means comprises preloading means for loading said springs prior to the mounting of said brackets on said beams.

12. A furnace body supporting structure as claimed in claim 10 in which said spring means comprises a dish Spring a i 

1. A furnace body supporting structure for blast furnace having a furnace shaft, comprising a ring plate on the bottom of the furnace shaft, a plurality of supporting columns arranged along the outer periphery of the furnace body, and spring means for absorbing the expansion and contraction of the furnace due to heating during operation and mounted between the respective supporting columns and the ring plate so as to be expandable and contractable in the vertical direction.
 2. A furnace body supporting structure as claimed in claim 1 in which said spring means comprises preloading means for loading said springs prior to the mounting of said ring plate on the spring means.
 3. A furnace body supporting structure as claimed in claim 1 in which said spring means comprises a dish spring.
 4. A furnace body supporting structure for blast furnaces having a furnace shaft, comprising brackets on the furnace shaft, a plurality of supporting columns arranged along the outer periphery of the furnace body, a beam mounted on each of the supporting columns and extending toward the furnace body, and spring means for absorbing the expansion and contraction of the furnace due to heating during operation and mounted between the respective beams and brackets so as to be expandable and contractable in the vertical direction.
 5. A furnace body supporting structure as claimed in claim 4 in which said spring means comprises preloading means for loading said springs prior to the mounting of said brackets on said beams.
 6. A furnace body supporting structure as claimed in claim 4 in which said spring means comprises a dish spring.
 7. A furnace body supporting structure for blast furnaces having a furnace shaft, comprising a ring plate on the bottom of the furnace shaft, a plurality of supporting columns arranged along the outer periphery of the furnace body, spring means for absorbing the expansion and contraction of the furnace due to heating during operation and mounted between the respective supporting columns and the ring plate so as to be expandable and contractable in the vertical direction, and a thrust block mounted between said ring plate and the corresponding supporting column and composed of an upper thrust block member and a lower thrust block member movable vertically relative to each other, the upper thrust block member being fixed to the ring plate and the lower thrust block member being fixed to the supporting column and the block members abutting each other to transmit to the supporting columns horizontal loads due to movement of the furnace body in The horizontal direction.
 8. A furnace body supporting structure as claimed in claim 7 in which said spring means comprises preloading means for loading said springs prior to the mounting of said ring plate on the spring means.
 9. A furnace body supporting structure as claimed in claim 7 in which said spring means comprises a dish spring.
 10. A furnace body supporting structure for blast furnaces having a furnace shaft, comprising brackets on the furnace shaft, a plurality of supporting columns arranged along the outer periphery of the furnace body, a beam mounted on each of the supporting columns and extending toward the furnace body, spring means for absorbing the expansion and contraction of the furnace due to heating during operation and mounted between the respective beams and brackets so as to be expandable and contractable in the vertical direction and a thrust block mounted between each beam and the corresponding bracket and composed of an upper thrust block member and a lower thrust block member movable vertically relative to each other, the upper thrust block member being fixed to the bracket and the lower thrust block member being fixed to the beam and the block members abutting each other to transmit to the supporting columns horizontal loads due to movement of the furnace body in the horizontal direction.
 11. A furnace body supporting structure as claimed in claim 10 in which said spring means comprises preloading means for loading said springs prior to the mounting of said brackets on said beams.
 12. A furnace body supporting structure as claimed in claim 10 in which said spring means comprises a dish spring. 